Mu‘allaq is defined by position at the beginning; mu‘dal is defined by two or more consecutive missing narrators. They therefore overlap without being identical.
Case 1: two consecutive links omitted from the compiler's side — both mu‘allaq and mu‘dal.
Case 2: only the first link omitted — mu‘allaq, but not mu‘dal on that basis.
Case 3: two consecutive intermediaries missing in the middle — mu‘dal, not mu‘allaq merely by that omission.
A narration may fit more than one technical label because the labels measure distinct properties of the chain.